Polymerization of resins



Patented n, 14, 1936,,

UNITED STATES PATENT OFFICE POLYMERIZATION F RESINS George Kenneth Anderson, Pittsburgh, Pa, as-

.signor to The Neville of Pennsylvania any, a corporation No Drawing. Original application August 3,}934,

' Serial No.. 738,300.

Divided and this application July 1, 1935, Serial No. 29,376. Renewed May 20, 1936 3 Claims. (CL zoo-n h contained in crude solvent naphtha, and other hydrocarbon liquids, containing bodies polymerizable to form resins of the coumarone type.

in a catalytic polymerization process, such as a process by which coumarone resin is produced by it the polymerization oiresin-forming bodies in crude solvent naphtha, or its equivalent, sulphuric acid is the most satisfactory catalyst, and the catalyst most generally employed' Concentrated sulphuric acid, 1. e. 66 Baume sulphuric 31% acid, is in some respects the id catalyst for use in such polymerizing process; it. are, however, at problems attendnot upon the use oi concentrated sulphuric acid, and these problems have" been solved more or up less satisfactorily by various methods oiproce dure. It is well known that in the polymerizing reaction which produces coumaroneresin, utium sulphuric :acid as a catalyst, there is a tendency for the reaction temperature to rise as rapidly in a surge, which produces a relatively great proportion of sludge, and which also tends to produce resin lacking in adequate solubility.

Although the rapid rise of reaction temperature may be tempered in various ways, there is present so during polymerization, a tendency toward intense local action in the reactive material, with attendant side reactions and the production oi unduly high polymers, and undesirable products of reaction. This eiiect also results in degree,

in the production of resins of inadequate solubility, and increases the difilculty of purification and recovery.

I have found that one satisfactory method of tempering the polymerizingaction of sulphuric 40 acid in the formation of resins, and of controlling the reaction by which polymerization proceeds in the polymerizable content of crude solvent naphtha, and the like, is to dilute concentrated sulphuric acid, employed as a catalyst, by means of a suitable organic solvent diluent.

For use as a; diluent for sulphuric acid in, for example, the production of coumarone resin by polymerization, it is essential that the diluent be a solvent for the sulphuric acid, and that it v should neither react with the inert constituents of the reaction mixture, nor produce of itself side reactions in the bodies available for polymerization. \It is also necessary that the diluent should 'either be non-reactive with the sulphuric acid, or that such reaction as may occur does not substantially impair the activity a the sulphuric acidas a catalyst.

I have found that isopropyl ether is a desirable diluent. This material conforms to 'the re-' quirements which have been explained above. W

The subject-matter herein disclosed and claimed is divisional of that disclosed in co-pending application Serial No. 738,300, filed August 3, 1934. In some respects theresults obtained from the use of isopropyl ether asa diluent for the sul- W phuric acid differ from the results obtained by the use of acetic acid as the diluent. it has been my experience that under identical conditions a dilute catalyst, in which isopropyl ether is the diluent, tends to produce a coumarone resin havw ins a higher melting point than that produced by a catalyst comprising sulphuric acid ina state of dilution in acetic acid, or its homologue.

An eple oi a polymerization process using isopropyl ether is a diluent ior sulphuric-acid W may be cited as follows:

Exam No. i

the. was 1%. I found the melting point of the 35 resin recovered from this polymerizing reaction to be 121 C. and that the resin precipitates from Stoddard solvent naphtha at 2 C. The color of the resin was dark amber.

Example No. 2

As another typical example as a use of isopropyl ether as a diluent, I conducted polymerizati'on in which the same proportion of sulphuric acid to isopropyl ether was used,and in which I used the same proportion of sulphuric acid to crude solvent naphtha. The crude solvent naphtha constituting the reaction material, however, contained 67.2% of polymerizable bodies. The 50 initial temperature of the reactive material was 17 C., and the maximum reaction temperature was below 42 C. The reaction proceeded to completion more slowly than in the next preceding example, and I allowed the catalyst to remain in 55 contact with the crude solvent naphtha for a period of 1% hours.

I have made no melting point test upon the resin produced. but observed that the resin cracked readily at normal room temperature, indicating roughly a melting point higher than about 90 C. The resin showed precipitation from Stoddard solvent naphtha at 9 C.

It is apparent from the above examples that the isopropyl ether, also, did not so react with the sulphuric acid as seriously to impair the catalytic value of the catalytic solution.

In both the runs utilizing isopropyl ether as a solvent diluent for the sulphuric acid, the reacted mixture was diluted with three times its volume of petroleum benzine in preparation for washing and neutralization.

In the examples given the reaction temperature was controlled by water jacketing. I have noted particularly that the control of reaction temperature may be readily eflectedwhen using isopropyl ether as a catalyst. In each oi the exam-' ples given water at tap temperature was used instead oi the refrigerated water commonly employed to control the temperature of a polymerizing reaction to produce resin.

In each example given, the period of reaction was relatively extended. There was no apparent substantial production of unduly high polymers,

and there appeared to be no products of side reactions.

It may be explained that in testing the solubility of the resin by precipitation from Stoddard solvent naphtha, I made in each instance a 20% solution by weight of the resin in the solvent, and cooled back to the temperature at which precipitation took place.

I claim as my invention:

1. In the process oi producing resin by the catalytic polymerization of crude solvent naphtha or a like reaction liquid containing bodies polymerizable to coumarone resin, the herein de scribed polymerization step which comprises preparing a catalytic solution by diluting sulphuric acid with isopropyl ether. and commingling the resulting catalytic solution with the body of reaction liquid, thereby eii'ecting in the'reactive liquid a polymerizing reaction produced by the catalytic solution.

2. The herein described polymerization step in accordance, with the procedure of claim 1 in which the isopropyi ether is in a volume substantially in excess of the volume of sulphuric acid.

3. The herein described polymerization step in accordance with the procedure of claim 1 in which the isopropyl ether is in a volume equal approximately to four times the volume of the sulphuric acid.

GEORGE KENNETH ANDERSON. 

